1. Field
Methods and apparatuses consistent with the exemplary embodiments relate to a transmitter, receiver and controlling method of transmitting and receiving Orthogonal Frequency-Division Multiplexing (OFDM) symbols.
2. Description of the Prior Art
DVB-T2 (Digital Video Broadcasting the Second Generation Terrestrial) is a second generation European terrestrial digital broadcast standard the performance of which has been improved from DVB-T which is adopted in more than 35 countries in the world including Europe. For DVB-T2, the transmission capacity and bandwidth have been improved by applying the latest technologies such as Low Density Parity Check (LDPC) codes and 256-QAM modulation method. Accordingly, it has an advantage of providing various high quality services such as high-definition television (HDTV) service in a limited bandwidth.
Meanwhile, DVB-NGH (Next Generation Handheld) has its basis on the concept of DVB-T2, and it is an extension of DVB-T2. DVB-NGH defines the next generation transmission system for broadcast digital terrestrial and hybrid (combination of satellite transmission and terrestrial wave) in portable terminals.
The DVB-T2 or DVB-NGH method uses an OFDM system which utilizes the Cyclic Delay Diversity (CDD) method in order to obtain the diversity effect. Herein, in the CDD method, at the frequency axis, the phase increases at a regular rate in each sub carrier, and thus there exists an echo with strong and long delay time, causing deterioration of performance of receivers in environments of increased selectivity.